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Concrete volume calculator
Estimate concrete volume and bags using the stated bag yield.
A clear answer. Here’s how.
Volume = length × width × depth, with centimetres converted to metres. Adds the chosen allowance and divides litres by your bag’s mixed yield, rounding bags up. This estimates quantity only, not a structural slab design or mix specification.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Slab length (m)
- 4
- Slab width (m)
- 3
- Slab depth (cm)
- 10
- Extra volume (%)
- 5
- Mixed yield per bag (litres)
- 12
Example result
- Net concrete volume
- 1.2 m³
- Volume including allowance
- 1.26 m³
- Equivalent litres
- 1,260
- Whole bags
- 105